References Tseng LW, Hughes D, Giger U. Evaluation Green RA, Thomas JS. Hemostatic Disorders: of point-of-care coagulation analyzer Coagulopathies and Thrombosis. In Ettinger for measurement of prothrombin time, SJ, Feldman EC: Textbook of Veterinary activated partial thromboplastin time, and Internal Medicine, 4th ed. Philadelphia, Pa: WB activated clotting time in dogs. Am J Vet Res. 2001;62:1455–1460. Saunders; 1995:1946–1963. IDEXX Coag Dx™ Suggested Readings Prothrombin Time (PT) Evatt BL, Brogan D, Triplett DA, et al. Effect of thromboplastin and analyzeration on the prothrombin time test. Clin Lab Haematol. Package Insert 1981;3:331–342. Gralnick HR, Kessler CM, Palmer R. The Prothrombin Time: Variables Affecting Results. In: Triplett DA, ed. “Standardization of Coagulation Assays: An Overview,’’ College of American Pathologists, Skokie, Il: 1982.

06-12895-01

Intended Use The PT is a unitized coagulation test intended Traditionally, the events leading to the for in vitro use in performing a quantitative, formation of a fibrin clot have been simplified one-stage prothrombin time. The PT test is in coagulation theory into two coagulation performed using fresh canine, feline or equine pathways: the intrinsic and extrinsic, both whole blood. This test is to be used in the leading to the common pathway and the Coag Dx™ Analyzer and is also compatible formation of a stable fibrin clot. The PT is with the SCA2000™ Coagulation Analyzer. a measure of the extrinsic and common This test is for veterinary use only and not coagulation pathways. for human diagnostic use. Principle of Operation Summary and Explanation The analyzer utilizes a mechanical end point The PT, a test of the extrinsic and common clotting mechanism in which clot formation coagulation pathways, can be performed occurs within the disposable PT cartridge. using fresh whole blood at the patient’s side. Following whole blood sample introduction, Since no specimen processing is required, PT the analyzer precisely measures 15 microliters results are obtained in less than two minutes. of blood and automatically moves it into the test channel within the PT cartridge. The Patient-side testing is especially valuable remainder of the blood sample, not needed during procedures and therapeutic for testing, is automatically drawn into the © 2007 IDEXX Laboratories, Inc. All rights reserved. interventions, for hemostasis assessment waste channel of the cartridge. Sample/ before or after blood transfusions, and for Coag Dx is a trademark or registered trademark of IDEXX Laboratories, One IDEXX Drive reagent mixing and test initiation are also Inc. in the United States and/or other countries. SCA2000 is a trademark of Westbrook, Maine 04092 diagnosis of anticoagulant rodenticide toxicity. performed automatically, requiring no operator Symbiotics, Inc. idexx.com

1 interaction. After mixing with the reagent, the Material provided 6. The analyzer emits a single beep when the Operating Precautions sample is moved back and forth within the test • PT test cartridges test is complete. Do NOT use cartridges that are past their channel and observed for clot formation. Material required (not provided) The test result, in seconds for whole blood, marked expiration date, or that have been The clot detection mechanism consists of a • Coagulation analyzer will remain on the screen until the test improperly stored. series of LED optical detectors aligned with cartridge is removed from the analyzer and • Plastic syringes Do NOT force a cartridge into the analyzer. the test channel of the cartridge. The speed for 120 seconds following its removal. If resistance to insertion is encountered, at which the blood sample moves between • 23-gauge needle or larger gently remove the cartridge and examine the the detectors is measured. As clot formation (for syringe sampling) Sample Collection cartridge slot. Remove any obstruction before begins, blood flow is impeded and the attempting further use of the analyzer. movement slows. The analyzer recognizes that Note: PT test cartridges must be at room Blood samples to be used for coagulation the clot end point has been achieved when the temperature prior to use. Once removed testing must be collected in the following Specimen collection and handling for movement decreases below a predetermined from the refrigerator, this may take up to manner to prevent contamination with tissue all coagulation testing requires careful rate. The PT whole blood clotting time is 60 minutes. For best results, the pouch thromboplastin, or indwelling intravenous (I.V.) adherence to guidelines. As with all diagnostic reported in whole seconds. should be opened immediately prior to solutions that interfere with the coagulation tests, test results should be scrutinized in testing. assays. Poorly collected blood samples with light of a specific patient’s condition and visible clotting or debris accumulation must be anticoagulant therapy. Any results exhibiting Reagents Test procedure discarded and a fresh sample collected. inconsistency with the patient’s clinical status Each box of PT test cartridges contains: Refer to the IDEXX Coag Dx™ Analyzer should be repeated or supplemented with Patient excitement should be minimized Operator’s Guide if any fault message should additional test data. • 10 pouches, each containing one PT test appear during this procedure. as this can increase platelet count, platelet cartridge and one dessicant aggregation, and the levels of von Willebrand The PT is affected by poor technique including 1. Insert a test cartridge into the cartridge Factor (vWF), fibrinogen, and Factors V and blood collection and the transfer of blood to The PT test cartridge is a self-contained opening of the analyzer. The cartridge must VIII. Prolonged venous stasis and excessive the sample well. The accuracy of the test is disposable test chamber preloaded with a be inserted with the blood reservoir facing probing for the vessel should be avoided. largely dependent upon the quality of the blood dried preparation of thromboplastin, stabilizers up. The analyzer will automatically identify Use of the cephalic or saphenous veins are specimen, which may be affected by: and buffers. Each cartridge is individually the test cartridge and display the test type. advised as bleeding is easier to control from packaged in a pouch. Cartridge pouches are • Foaming of the sample these sites (Green, et al, 1995). If a syringe stamped with a lot-specific expiration date. 2. During the warming stage, observe the display for fault messages. is used, it should have a 23-gauge needle or • Hemolysis of the sample Caution: All used test cartridges should be larger. Use of excessive force when expelling • Clotted or partially clotted blood considered as potentially infectious, handled The analyzer emits an audible tone when it the blood specimen through the needle may with care and disposed of properly. is ready and alternately displays the “Add cause hemolysis. Sample” and “Press Start” messages. The Performance Characteristics Note: Samples must not be collected until analyzer remains in the “Ready” mode for Reference range Storage and Stability five minutes before a “START... timeout” the analyzer indicates “Add Sample” and Whole blood samples were obtained from When refrigerated (2°–8°C), the foil-pouched message displays. If this occurs, a new test “Press Start.” normal healthy animals and tested with the PT cartridges are stable until the marked cartridge must be placed in the analyzer. PT assay. Reference ranges are: expiration date. Room temperature storage Syringe sample, from indwelling line 3. Obtain the blood sample. (See the Sample Note: The amount of blood required to (15°–30°C) is optional for unopened, pouched Collection section for more information.) Species Canine Feline Equine cartridges. PT cartridges should not be adequately flush the line until it is free of contaminants is dependent on the amount Reference Range 11–14 13–22 15–18 exposed to temperatures in excess of 37°C. 4. Immediately dispense one drop of blood (sec) into the sample well of the test cartridge; of solution contained within the line. Greater Note: Room temperature redating is to a fill from the bottom of the well up. This may volumes will be required to clear longer lines. maximum of 4 weeks, but must never exceed be done either with or without a needle. A Limitations the marked expiration date. Redating is Using a tuberculin (1 cc) or 3 cc syringe, sufficient quantity of blood must be added Whole blood PT test results under 7 seconds necessary if stored at room temperature. Mark collect a minimum of 0.2 cc of blood from a directly to the center sample well to fill it or over 100 seconds are not reported. Instead, the outer box with the new expiration previously flushed access port. Do not allow flush to the top. Should a large drop of either an “Out of range - Lo” or “Out of range date when cartridges are stored at room bubbles to form in the syringe. blood extend above the center sample - Hi” message is displayed. temperature. well, push it over into the outer sample well. Syringe sample, from a venipuncture 5. Press the Start key. A single beep will 1. Prepare the venipuncture site by cleansing Operating Instructions signal the start of the test. The analyzer with alcohol and allowing to air-dry Before performing any assay, refer to the automatically mixes the sample with the completely. IDEXX Coag Dx™ Analyzer Operator’s Guide reagent and detects clot. 2. Obtain a minimum of 0.2 cc of blood. for detailed operating instructions.

2 3